I sincerely believe that you could get everything done in a day with a rented, quality trencher. You might think of this as 2 stages, main lines giving yourself abundant distribution (future proof and overkill) and branch lines around your structures and a grid in between based on the sprinkler head broadcast distances for your water pressure.
Over the last year, I installed 1000's feet of PVC water lines (some electric and cable/data/phone also) for house, mother-in-law house, food garden, wild flower garden, shop, barn, 4 acres of irrigation, and a 1300' foot run for a tree line. I really don't know how many feet total, but I'm guessing that I dug about 1/8 with a shovel and pick and 7/8 with three different types of rented trenchers. Importantly, I did put all of these lines at 2'-4' depth for the occassional hard freezes that we have in North Texas; the person that I bought the property from told me a story about his first Christmas on the property when they had frozen, in-ground (8"-12") water lines for 14 days leaving a dozen family members (some extended family included) with only an outhouse and trucked in water to use.
I sat down with a survey of my property; quickly drew a trench layout that served these structures to my well (large storage tank) and the pole where I get my power and cable. I cut these main trenches in one day of rental. When I laid these lines, I oversized with 1.5" PVC because I didn't know how much flow would be needed in any given area, plus I added dozens of ball valves so I had lots of options to tie into the mains since I hadn't planned every branch/accessory detail I wanted to get water flowing to the main house.
For all the branch lines which included most of the sprinkler system and all sorts of hose bibs around the property, I looked up the broadcast distance of rotary sprinkler heads for my water pressure (about 20'-25'), and then in one day I cut all the trenches for branch lines along the perimeter of all structures, planting beds, drives, and the boundary lines of my "residential area" with a 45' grid spaced inside the perimeters.
The 1300' cut for a 600' tree line was the most recent project and cut in one day.
I dug 300' of all this with hand tools in very hard ground and almost ruined myself in 100+ heat.
I backfilled and compacted all my trenches by hand. For most of this, I backfilled over several months. I learned along the way that if I didn't backfill before the next rain or many rains that it was very difficult to backfill the trench with the spoils. By the time I did the 1300', I decided to backfill the same day of or day after cutting the trench so that the spoils were still loose and easy to work back into the trench. I only wish I had my tractor sooner!!! :confused2:
My enthusiasm for buried lines caused quite a few laughs with some tradesmen that were doing work with me. :laughing:
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